[IggleSniggle]

Maybe something like Observable (the product not the pattern) + TypeScript?

I’ve been thinking recently that TypeScript, when considered by itself (ie, just the type system), is quickly becoming a kind of flexible type database around a very loose language.

You can force TypeScript to figure things like:

type One = 1; type Two = 2; type addOneAndTwo = One + Two;

But its very brittle and difficult to accomplish, especially if you wish to couple this back to the runtime values.

If these ever become language features, I can see this powering the thing you’re describing: a capability that gives you flexible loose JavaScript for the non-programmers that can also be iteratively tightened, possibly with a reactive view fronting all of it.